Wessels Marlene, Oberfeld Daniel
Institute of Psychology, Section Experimental Psychology, Johannes Gutenberg-Universität Mainz, Wallstrasse 3, 55122, Mainz, Germany.
Heliyon. 2024 Mar 6;10(6):e27483. doi: 10.1016/j.heliyon.2024.e27483. eCollection 2024 Mar 30.
When a pedestrian intends to cross the street, it is essential for safe mobility to correctly estimate the arrival time (time-to-collision, TTC) of an approaching vehicle. However, visual perception of acceleration is rather imprecise. Previous studies consistently showed that humans (mostly) disregard acceleration, but judge the TTC for an object as if it were traveling at constant speed (first-order estimation), which is associated with overestimated TTCs for positively accelerating objects. In a traffic context, such TTC overestimation could motivate pedestrians to cross in front of an approaching vehicle, although the time remaining is not sufficiently long. Can a simple acceleration signal help improve visual TTC estimation for accelerating objects? The present study investigated whether a signal that only indicates whether a vehicle is accelerating or not can remove the first-order pattern of overestimated TTCs. In a virtual reality simulation, 26 participants estimated the TTC of vehicles that approached with constant velocity or accelerated, from the perspective of a pedestrian at the curb. In half of the experimental blocks, a light band on the windshield illuminated whenever the vehicle accelerated but remained deactivated when the vehicle travelled at a constant speed. In the other blocks, the light band never illuminated, regardless of whether or not the vehicle accelerated. Participants were informed about the light band function in each block. Without acceleration signal, the estimated TTCs for the accelerating vehicles were consistent with an erroneous first-order approximation. In blocks with acceleration signal, participants substantially changed their estimation strategy, so that TTC overestimations for accelerating vehicles were reduced. Our data suggest that a binary acceleration signal helps pedestrians to effectively reduce the TTC overestimation for accelerating vehicles and could therefore increase pedestrian safety.
当行人打算过马路时，正确估计驶来车辆的到达时间（碰撞时间，TTC）对于安全通行至关重要。然而，对加速度的视觉感知相当不准确。先前的研究一致表明，人类（大多）会忽略加速度，而是将物体的TTC判断为仿佛它在以恒定速度行驶（一阶估计），这与对正向加速物体的TTC高估有关。在交通场景中，这种TTC高估可能会促使行人在驶来的车辆前方过马路，尽管剩余时间并不足够长。一个简单的加速度信号能否帮助改善对加速物体的视觉TTC估计呢？本研究调查了一个仅指示车辆是否在加速的信号是否能消除TTC高估的一阶模式。在虚拟现实模拟中，26名参与者从路边行人的视角估计以恒定速度接近或加速的车辆的TTC。在一半的实验块中，每当车辆加速时，挡风玻璃上的一条光带就会亮起，但当车辆以恒定速度行驶时，光带保持关闭状态。在其他实验块中，无论车辆是否加速，光带都不会亮起。在每个实验块中，参与者都被告知光带的功能。没有加速度信号时，对加速车辆的估计TTC与错误的一阶近似一致。在有加速度信号的实验块中，参与者大幅改变了他们的估计策略，从而减少了对加速车辆的TTC高估。我们的数据表明，一个二元加速度信号有助于行人有效减少对加速车辆的TTC高估，因此可以提高行人安全性。
